Ég spyr um þýðingu orðsins þegar orðabókin gefur ekki nægar upplýsingar.

Spyr is the 1st person singular present tense form of the verb að spyrja (to ask).

So:

• að spyrja = to ask
• ég spyr = I ask

This sentence uses the present tense because it describes a general or habitual action: I ask about a word’s translation when the dictionary does not give enough information.

In Icelandic, spyrja um means to ask about something.

So:

• spyrja = to ask
• spyrja um eitthvað = to ask about something

That is why the sentence has:

• Ég spyr um þýðingu... = I ask about the translation...

The preposition um is required by this meaning, just as English uses about.

Because the preposition um normally takes the accusative case.

The noun is:

• þýðing = translation

But after um, it becomes accusative singular:

• um þýðingu = about a translation / about the translation

So the ending changes because of case.

Orðsins is the genitive singular of orð (word).

Here it means of the word:

• þýðing orðsins = the translation of the word

This is a very common Icelandic pattern: one noun is followed by another noun in the genitive to show possession or relationship.

Compare:

• hús mannsins = the man’s house / the house of the man
• merking orðsins = the meaning of the word
• þýðing orðsins = the translation of the word

Orðabókin means the dictionary.

Icelandic usually adds the definite article to the end of the noun instead of using a separate word like English the.

So:

• orðabók = dictionary
• orðabókin = the dictionary

The ending -in here is the suffixed definite article.

Because upplýsingar is the direct object of gefur (gives), so it is in the accusative plural, and the adjective must agree with it.

Breakdown:

• upplýsing = piece of information / information item
• upplýsingar = information / pieces of information

In this sentence:

• gefur ekki nægar upplýsingar = does not give enough information

Agreement:

• nægar = enough / sufficient, feminine plural accusative
• upplýsingar = feminine plural accusative

So the adjective and noun match in gender, number, and case.

That is a vocabulary difference between the two languages.

In Icelandic, upplýsingar is very often used in the plural where English simply says information.

So:

• nægar upplýsingar = enough information

Even though English uses an uncountable noun, Icelandic commonly uses a plural form here. This is very natural Icelandic.

In a normal main or subordinate clause, ekki usually comes after the finite verb.

So:

• orðabókin gefur ekki... = the dictionary does not give...

This placement is very common in Icelandic:

• Ég skil ekki. = I do not understand.
• Hún kemur ekki. = She is not coming.

So gefur ekki is the expected word order.

Þegar means when here. It introduces a subordinate clause:

• þegar orðabókin gefur ekki nægar upplýsingar
• when the dictionary does not give enough information

This clause tells us when or under what circumstances the speaker asks.

In this sentence, the meaning is more general or habitual:
whenever / when the dictionary does not provide enough information.

Because after þegar, Icelandic uses a normal subordinate clause structure here:

• þegar orðabókin gefur ekki nægar upplýsingar

That is:

1. conjunction: þegar
2. subject: orðabókin
3. finite verb: gefur
4. negation: ekki
5. object: nægar upplýsingar

This is a standard and natural order.

A useful extra point: if the þegar-clause came first in the sentence, the main clause would usually show inversion:

• Þegar orðabókin gefur ekki nægar upplýsingar, spyr ég um þýðingu orðsins.

Notice spyr ég, not ég spyr.

Usually simply I ask.

The Icelandic present tense can cover several English ideas depending on context:

• I ask
• I am asking
• sometimes even a habitual I ask whenever...

In this sentence, the best interpretation is a habitual present:

• Ég spyr ... þegar ...
• I ask ... when / whenever ...

So it describes something the speaker typically does.

A few key points:

• é is pronounced roughly like ye in many contexts
  
  • Ég sounds approximately like yeg
• þ is like th in thing
  • þýðingu
• ð is like th in this
  
  • þýðingu, orð, orðabókin

A few words roughly approximated:

• Ég ≈ yeg
• spyr ≈ speer (very approximate)
• þýðingu ≈ THEE-thing-gu (very approximate)
• orðsins ≈ orth-sins
• orðabókin ≈ OR-tha-boh-kin

These are only rough guides. Icelandic vowels and r sounds are better learned by listening to native audio.

Yes. A very natural alternative is:

• Þegar orðabókin gefur ekki nægar upplýsingar, spyr ég um þýðingu orðsins.

This means the same thing.

The important change is word order in the main clause:

• Ég spyr ...
  but
• Þegar ..., spyr ég ...

That inversion happens because the sentence begins with another element before the main verb.

It breaks down like this:

• Ég = I
• spyr um = ask about
• þýðingu orðsins = the translation of the word
• þegar = when
• orðabókin gefur ekki nægar upplýsingar = the dictionary does not give enough information

So the grammar is:

Subject + verb + prepositional phrase + subordinate clause

More literally:

I ask about translation-of-the-word when the-dictionary gives not enough information.

That kind of literal breakdown can help you see how Icelandic case endings are working.